1. Field of the Invention
The present invention relates in general to vehicular control devices, and more specifically, to a vehicular illuminated control device using touch switches.
2. Description of the Related Art
Vehicle door lock mechanisms include a plurality of devices for locking and unlocking a vehicle door. Such mechanical devices include a door lock stem and a vehicle door key. Other devices utilize an electronically controlled door lock actuator that engages the lock mechanism. The door lock actuator is electrically driven and is often controlled by a relay or an electronic control module. The electronic control module receives a locking or unlocking command via a wireline or a radio frequency (RF) signal from a user input control device.
One such user input control device includes a keyless entry pad typically mounted on a vehicle door or other vehicle panel. The keyless entry pad includes a plurality of buttons for transmitting a signal via a wireline to the electronic control module. The keyless entry touch pad further includes a plurality of graphics disposed on an exterior surface of each button. Each graphic identifies the location of a respective button. An exterior casing or weatherproof seals are used to conceal any gaps or openings between the bezel and buttons which assist in deterring contaminants or water from entering any of the gaps or openings. However such exterior casings or waterproof buttons require an additional cost to the vehicle manufacturers.
The graphical displays disposed on the exterior surface of each key or button are easily visible during the daylight, but they are not so easily visible during night hours in less ambient light. During the nighttime in poorly lit or no light conditions, the operator must have to either recall the location of the each button on the keyless entry touch pad or locate a respective touch pad switch and depress it for illuminating the keyless entry touch pad. The keyless entry pad is typically illuminated by direct lighting such as one or more LED's located below the exterior surface of the buttons directly focused at the graphics of the touch pad switch or by the use of lightpipes. Direct lighting often requires proper positioning and tight assembly tolerances for backlighting the graphics evenly. Lightpiping involves the added cost of incorporating lightpipes into the keyless entry device.